1 files changed, 55 insertions, 34 deletions

diff --git a/mm/memory.c b/mm/memory.c
index 0f60baf6f69b..2998cfc12f5b 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -549,10 +549,10 @@ int copy_page_range(struct mm_struct *dst_mm, struct mm_struct *src_mm,
         return 0;
 }
 
-static void zap_pte_range(struct mmu_gather *tlb,
+static unsigned long zap_pte_range(struct mmu_gather *tlb,
                                 struct vm_area_struct *vma, pmd_t *pmd,
                                 unsigned long addr, unsigned long end,
-                                struct zap_details *details)
+                                long *zap_work, struct zap_details *details)
 {
         struct mm_struct *mm = tlb->mm;
         pte_t *pte;
@@ -563,10 +563,15 @@ static void zap_pte_range(struct mmu_gather *tlb,
         pte = pte_offset_map_lock(mm, pmd, addr, &ptl);
         do {
                 pte_t ptent = *pte;
-                if (pte_none(ptent))
+                if (pte_none(ptent)) {
+                        (*zap_work)--;
                         continue;
+                }
                 if (pte_present(ptent)) {
                         struct page *page = NULL;
+
+                        (*zap_work) -= PAGE_SIZE;
+
                         if (!(vma->vm_flags & VM_RESERVED)) {
                                 unsigned long pfn = pte_pfn(ptent);
                                 if (unlikely(!pfn_valid(pfn)))
@@ -624,16 +629,18 @@ static void zap_pte_range(struct mmu_gather *tlb,
                 if (!pte_file(ptent))
                         free_swap_and_cache(pte_to_swp_entry(ptent));
                 pte_clear_full(mm, addr, pte, tlb->fullmm);
-        } while (pte++, addr += PAGE_SIZE, addr != end);
+        } while (pte++, addr += PAGE_SIZE, (addr != end && *zap_work > 0));
 
         add_mm_rss(mm, file_rss, anon_rss);
         pte_unmap_unlock(pte - 1, ptl);
+
+        return addr;
 }
 
-static inline void zap_pmd_range(struct mmu_gather *tlb,
+static inline unsigned long zap_pmd_range(struct mmu_gather *tlb,
                                 struct vm_area_struct *vma, pud_t *pud,
                                 unsigned long addr, unsigned long end,
-                                struct zap_details *details)
+                                long *zap_work, struct zap_details *details)
 {
         pmd_t *pmd;
         unsigned long next;
@@ -641,16 +648,21 @@ static inline void zap_pmd_range(struct mmu_gather *tlb,
         pmd = pmd_offset(pud, addr);
         do {
                 next = pmd_addr_end(addr, end);
-                if (pmd_none_or_clear_bad(pmd))
+                if (pmd_none_or_clear_bad(pmd)) {
+                        (*zap_work)--;
                         continue;
-                zap_pte_range(tlb, vma, pmd, addr, next, details);
-        } while (pmd++, addr = next, addr != end);
+                }
+                next = zap_pte_range(tlb, vma, pmd, addr, next,
+                                                zap_work, details);
+        } while (pmd++, addr = next, (addr != end && *zap_work > 0));
+
+        return addr;
 }
 
-static inline void zap_pud_range(struct mmu_gather *tlb,
+static inline unsigned long zap_pud_range(struct mmu_gather *tlb,
                                 struct vm_area_struct *vma, pgd_t *pgd,
                                 unsigned long addr, unsigned long end,
-                                struct zap_details *details)
+                                long *zap_work, struct zap_details *details)
 {
         pud_t *pud;
         unsigned long next;
@@ -658,15 +670,21 @@ static inline void zap_pud_range(struct mmu_gather *tlb,
         pud = pud_offset(pgd, addr);
         do {
                 next = pud_addr_end(addr, end);
-                if (pud_none_or_clear_bad(pud))
+                if (pud_none_or_clear_bad(pud)) {
+                        (*zap_work)--;
                         continue;
-                zap_pmd_range(tlb, vma, pud, addr, next, details);
-        } while (pud++, addr = next, addr != end);
+                }
+                next = zap_pmd_range(tlb, vma, pud, addr, next,
+                                                zap_work, details);
+        } while (pud++, addr = next, (addr != end && *zap_work > 0));
+
+        return addr;
 }
 
-static void unmap_page_range(struct mmu_gather *tlb, struct vm_area_struct *vma,
+static unsigned long unmap_page_range(struct mmu_gather *tlb,
+                                struct vm_area_struct *vma,
                                 unsigned long addr, unsigned long end,
-                                struct zap_details *details)
+                                long *zap_work, struct zap_details *details)
 {
         pgd_t *pgd;
         unsigned long next;
@@ -679,11 +697,16 @@ static void unmap_page_range(struct mmu_gather *tlb, struct vm_area_struct *vma,
         pgd = pgd_offset(vma->vm_mm, addr);
         do {
                 next = pgd_addr_end(addr, end);
-                if (pgd_none_or_clear_bad(pgd))
+                if (pgd_none_or_clear_bad(pgd)) {
+                        (*zap_work)--;
                         continue;
-                zap_pud_range(tlb, vma, pgd, addr, next, details);
-        } while (pgd++, addr = next, addr != end);
+                }
+                next = zap_pud_range(tlb, vma, pgd, addr, next,
+                                                zap_work, details);
+        } while (pgd++, addr = next, (addr != end && *zap_work > 0));
         tlb_end_vma(tlb, vma);
+
+        return addr;
 }
 
 #ifdef CONFIG_PREEMPT
@@ -724,7 +747,7 @@ unsigned long unmap_vmas(struct mmu_gather **tlbp,
                 unsigned long end_addr, unsigned long *nr_accounted,
                 struct zap_details *details)
 {
-        unsigned long zap_bytes = ZAP_BLOCK_SIZE;
+        long zap_work = ZAP_BLOCK_SIZE;
         unsigned long tlb_start = 0;    /* For tlb_finish_mmu */
         int tlb_start_valid = 0;
         unsigned long start = start_addr;
@@ -745,27 +768,25 @@ unsigned long unmap_vmas(struct mmu_gather **tlbp,
                         *nr_accounted += (end - start) >> PAGE_SHIFT;
 
                 while (start != end) {
-                        unsigned long block;
-
                         if (!tlb_start_valid) {
                                 tlb_start = start;
                                 tlb_start_valid = 1;
                         }
 
-                        if (is_vm_hugetlb_page(vma)) {
-                                block = end - start;
+                        if (unlikely(is_vm_hugetlb_page(vma))) {
                                 unmap_hugepage_range(vma, start, end);
-                        } else {
-                                block = min(zap_bytes, end - start);
-                                unmap_page_range(*tlbp, vma, start,
-                                                start + block, details);
+                                zap_work -= (end - start) /
+                                                (HPAGE_SIZE / PAGE_SIZE);
+                                start = end;
+                        } else
+                                start = unmap_page_range(*tlbp, vma,
+                                                start, end, &zap_work, details);
+
+                        if (zap_work > 0) {
+                                BUG_ON(start != end);
+                                break;
                         }
 
-                        start += block;
-                        zap_bytes -= block;
-                        if ((long)zap_bytes > 0)
-                                continue;
-
                         tlb_finish_mmu(*tlbp, tlb_start, start);
 
                         if (need_resched() ||
@@ -779,7 +800,7 @@ unsigned long unmap_vmas(struct mmu_gather **tlbp,
 
                         *tlbp = tlb_gather_mmu(vma->vm_mm, fullmm);
                         tlb_start_valid = 0;
-                        zap_bytes = ZAP_BLOCK_SIZE;
+                        zap_work = ZAP_BLOCK_SIZE;
                 }
         }
 out: